| ( | 240000 | − | X | ) | ÷ | X | × | 100 100 | = | 20 100 |
| Multiply both sides of the equation by: | X |
| ( | 240000 | − | X | ) | × | 100 100 | = | 20 100 | X |
| 240000 | × | 100 100 | − | X | × | 100 100 | = | 20 100 | X |
| 240000 | − | X | × | 100 100 | = | 20 100 | X |
| - | 100 100 | X | − | 20 100 | X | = | - | 240000 |
| - | 6 5 | X | = | - | 240000 |
| 240000 | = | 6 5 | X |
6 5 | X | = | 240000 |
| X | = | 240000 | ÷ | 6 5 |
| = | 240000 | × | 5 6 |
| = | 40000 | × | 5 |
| X | = | 200000 |